4/17/2017 Minnesota Lions Eye Bank Mission Minnesota Lions Eye Bank Descemet Membrane Laboratory Department To help restore sight through eye donation Endothelial Keratoplasty (DMEK) Preparation Jeff Justin Clinical Laboratory Scientist Dr. Eduard Zirm Corneal Transplant History History • 1905 - First human cornea transplant 1905 First successful • 1925 - Helen Keller challenge to Lions cornea transplant is performed in members to be “Knights of the Blind” Czech Republic. • 1937 - First U.S. Cornea Transplant • 1944 - First U.S. Eye Bank • 1960 - Minnesota Lions Eye Bank • 1961 - Eye Bank Association of America Clinical & Experimental Ophthalmology Volume 33, Issue 6, pages 642-657, 5 DEC 2005 DOI: 10.1111/j.1442-9071.2005.01134.x http://onlinelibrary.wiley.com/doi/10.1111/j.1442-9071.2005.01134.x/full#f5 1
4/17/2017 Cross section History – Cornea Transplants Eye Recovery • 1974 < 5,000 cornea transplants • Procurement - Enucleation • 2016 > 80,000 cornea transplants • Cornea transplants 95 % successful Eye Recovery Evaluation Sclera • Preserved cornea in viewing • Procurement - In Situ chamber • Whole sclera anchors prosthetic eyes after enucleation. • Quarter sclera is used to cover glaucoma shunts. 2
4/17/2017 Ocular Coherence Tomography Specular Microscopy Slit Lamp Biomicroscope • Micron-resolution Endothelial cell count images • Shows structural • >2000/mm² for • features e.g., scars and endothelial transplant Scars • Minimum cell density defects • Edema • Allows precise needed for adequate • Defects function is ≈ 400−700 measurement of cornea • Guttae dimensions cells/mm². • • Used pre and post Infiltrates processing • Foreign bodies Pachymetry Suitability Penetrating Keratoplasty (PK) • Corneal condition determines which surgery it’s suitable for: – Penetrating Keratoplasty – Anterior Lamellar Keratoplasty – Deep Anterior Lamellar Keratoplasty – Endothelial Keratoplasties – Keratolimbal Allograft – Keratoprosthesis 3
4/17/2017 Penetrating Keratoplasty (PK) Superficial Corneal Scar Anterior Lamellar Graft (ALK) Cross section Keratolimbal Allograft (KLAL) Corneal endothelium for Stem Cell Deficiency • Purpose: control hydration (maintain stromal deturgescence) and deliver nutrients and other molecules from the aqueous humor • 6000 cells/mm² at birth • 3400/mm² at age 15 • 2300/mm² at age 85 4
4/17/2017 Descemet’s Stripping Processed Tissue Automated Endothelial Processing - DSAEK Endothelial Keratoplasty Keratoplasty (DSAEK) • DSAEK Descemet Stripping Automated Endothelial Keratoplasty • DMEK Descemet Membrane Endothelial Keratoplasty Microkeratome Dissection Descemet’s Stripping Procedure Graft Insertion Range of thickness for graft: 50-150 µm 5
4/17/2017 DMEK Unfolding of graft DSAEK Loading the inserter Injecting graft Double scroll 6
4/17/2017 Unfolding graft Unfolding graft Graft in place DMEK vs DSAEK Descemets Membrane Cornea suitability for DMEK • More anatomic with no optical interface • Serves as the basement membrane of • >50 yrs old− scroll not as tight & thicker • Better refractive outcomes/visual acuity the endothelial cells • Endothelial cell count >2200 cells/mm² • May have lower rejection rates • Cells continually secrete collagen • No defects or scars affecting Descemets • Faster recovery throughout life • Healthy endothelium • Surgically more challenging as a • 3 µm thick at birth • IOL scars- surgeon preference procedure • 10-13 µm by age 70 • May have a higher dislocation rate • Diabetes- ok 7
4/17/2017 Tissue Utilization – US Eye Banks DMEK preparation Indications for DMEK/DSAEK Distribution 2016 2015 2014 2013 2012 Corneal Grafts Total 82,994 79,304 76,431 72,736 68,681 • Secure on suction base • Similar for each Penetrating keratoplasty 38,413 39,554 38,919 36,998 36,716 • Score peripheral membrane • Post cataract surgery edema Anterior Lamellar Keratoplasty 2,386 2,201 1,953 2,009 1,855 Endothelial keratoplasty 32,221 30,710 28,961 27,298 24,277 • Free up edges • Fuchs’ dystrophy Keratolimbal Allograft 97 107 88 110 97 Glaucoma Shunt Patch or 917 527 755 687 676 • Peel membrane off stoma • Repeat corneal transplant other non keratoplasty use • Trephine and/or apply “S” stamp if • Other causes of endothelial dysfunction Other keratoplasty 65 19 17 17 44 Unknown or Unspecified 1,514 1,142 1,026 1,068 1,554 requested • Unspecified Sclera 3,225 3,225 3,345 3,369 3,497 Research 17,023 16,924 17,670 17,384 19,320 Training 9,916 10,003 9,295 7,451 6,850 Domestic Endothelial Information Keratoplasty 2013 - 2016 Jeff Justin Domestic Surgery Use 2016 2015 2014 2013 Laboratory Scientist Total Endothelial Keratoplasty procedures 28,327 27,208 25,965 24,987 JJJustin@umn.edu DSEK, DSAEK, DLEK Procedures 21,868 22,514 23,100 23,465 612-625-3118 DMEK or DMAEK Procedures 6,459 4,694 2,865 1,522 www.a Gift of Sight .org 8
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